[Proj4j] Enhancements for Projection classes

[Martin Davis]

All,

I just commited a significant changed to the Projection class API.
This is to use the word "project" rather than "transform" in the publc
methods.  I think this is more in line with the semantics of the
projection classes.

I also improved the Javadoc to be clearer about what units are used by
various methods.

The overall CoordinateTransform classes still use the term
"transform", since a coordinate transformation may include any or all
of a projection, datum transformation, and reprojection.

I also fixed the ProjectionGridRoundTripper to work!

Martin